Investigation and
Experimentation
The Scientific Method,
Lab Equipment, Measuring,
and
Lab Safety
Standards
•
1. Scientific progress is made by asking meaningful questions and conducting
careful investigations. As a basis for understanding this concept and addressing the
content of the other four strands, students should develop their own questions
and perform investigations. Students will:
•
a. Select and use appropriate tools and technology (such as computer-linked
probes, spreadsheets, and graphing calculators) to perform tests, collect data,
analyze relationships, and display data.
•
b. Identify and communicate sources of unavoidable experimental error.
•
c. Identify possible reasons for inconsistent results, such as sources of error or
uncontrolled conditions.
•
d. Formulate explanations by using logic and evidence.
•
e. Solve scientific problems by using quadratic equations and simple trigonometric,
exponential, and logarithmic functions.
•
f. Distinguish between hypothesis and theory as scientific terms.
•
g. Recognize the usefulness and limitations of models and theories as scientific
representations of reality.
Standards Cont.
•
h. Read and interpret topographic and geologic maps.
•
i. Analyze the locations, sequences, or time intervals that are characteristic of
natural phenomena (e.g., relative ages of rocks, locations of planets over time, and
succession of species in an ecosystem).
•
j. Recognize the issues of statistical variability and the need for controlled tests.
•
k. Recognize the cumulative nature of scientific evidence.
•
l. Analyze situations and solve problems that require combining and applying
concepts from more than one area of science.
•
m. Investigate a science-based societal issue by researching the literature,
analyzing data, and communicating the findings. Examples of issues include
irradiation of food, cloning of animals by somatic cell nuclear transfer, choice of
energy sources, and land and water use decisions in California.
•
n. Know that when an observation does not agree with an accepted scientific
theory, the observation is sometimes mistaken or fraudulent (e.g., the Piltdown
Man fossil or unidentified flying objects) and that the theory is sometimes wrong
(e.g., the Ptolemaic model of the movement of the Sun, Moon, and planets).
The Scientific Method
Make
Observations
Ask
Questions
Formulate a Possible
Hypothesis Explanations
Test the
Hypothesis
Design
Experiment
Collect Data
Measurements
Draw Your
Conclusions
Analyze
the Data
Calculations,
Graphs, Tables
Measurement
Length
Time
Mass
Units
meters,
centimeters, feet,
inches, miles
seconds, minutes,
hours, days, years
grams, kilograms,
pounds, ounces
Units
How we
(abbrev.) measure it
m, cm,
Ruler,
km, ft, in, measuring
mi
tape
s, min,
Clock,
hr, dy, yr stopwatch
g, kg, lb, Scale, triple
oz
beam
balance
Measurement
Volume
Temperature
Units
Units
How we
(abbrev.) measure it
milliliters, liters,
mL, L,
graduated
cubic centimeters, cm3, ft3,
cylinder
cubic feet, gallons
gal
degrees Celsius,
°C, °F, K
thermodegrees
meter
Fahrenheit, Kelvin
Measuring Volume
Graduated Cylinders
Measure
from the
bottom of
the meniscus
(U-shape).
What is the volume
of liquid in this
graduated cylinder?
What is the volume
of liquid in this
graduated cylinder?
1 Notch below
800 mL, so…
about 790 mL
More Experiment Vocabulary
More Experiment Vocabulary
Converting Between Units
(the Chemistry way)
• Even if you can do the conversion in your head or
by only using a calculator, you need to practice
following the steps.
• Eventually the problems in this Chemistry class
will become too complicated to do without
writing out the steps.
• You can still use a calculator, just save it for the
last step.
• You will only get full credit for these questions by
showing your work. You will get partial credit
even if you got the wrong answer if you followed
the steps.
Converting Between Units
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Step 1) Put what you are starting with over 1.
? ft  10 in
1
Converting Between Units
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Step 2) Multiply it by the conversion factor as a
fraction. Put the units that you are
getting rid of on the bottom. Put the
units you want on the top.
1 ft
? ft  10 in
×
1
12 in
Converting Between Units
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Step 3) Cancel out the units that are on both
the top and bottom.
1 ft
? ft  10 in
×
1
12 in
Converting Between Units
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Step 4) Multiply everything on the top.
Multiply everything on the bottom.
Keep the units that have not been
cancelled out.
1 ft
10
? ft  10 in
ft
×
=
1
12 in
12
Converting Between Units
1 ft = 12 in
Example #1: Convert 10 inches to feet.
Step 5) Divide the top by the bottom with a
calculator to get a decimal.
1 ft
10
? ft  10 in
ft = 0.83 ft
×
=
1
12 in
12
Converting Between Units
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Step 1) Put what you are starting with over 1.
? L  2.5 gal
1
Converting Between Units
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Step 2) Multiply it by the conversion factor as a
fraction. Put the units that you are
getting rid of on the bottom. Put the
units you want on the top.
? L  2.5 gal 3.8 L
×
1
1 gal
Converting Between Units
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Step 3) Cancel out the units that are on both
the top and bottom.
? L  2.5 gal 3.8 L
×
1
1 gal
Converting Between Units
1 gal = 3.8 L
Example #2: Convert 2.5 gallons to liters.
Step 4) Multiply everything on the top.
Multiply everything on the bottom.
Keep the units that have not been
cancelled out.
? L  2.5 gal 3.8 L
×
= 9.5 L
1
1 gal
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #1: Convert 78 centimeters to feet.
Step 1) Put what you are starting with over 1.
? ft  78 cm
1
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Step 2) Multiply it by the 1st conversion factor
as a fraction. Put the units that you are
getting rid of on the bottom. Put the
units you want on the top.
? ft  78 cm 1 in
×
1
2.5 cm
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Step 3) Cancel out the units that are on both
the top and bottom.
? ft  78 cm 1 in
×
1
2.5 cm
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Step 4) Multiply it by the 2nd conversion factor
as a fraction. Put the units that you are
getting rid of on the bottom. Put the
units you want on the top.
1 ft
? ft  78 cm 1 in
×
×
1
2.5 cm 12 in
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Step 5) Cancel out the units that are on both
the top and bottom.
1 ft
? ft  78 cm 1 in
×
×
1
2.5 cm 12 in
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Step 6) Multiply everything on the top.
Multiply everything on the bottom.
Keep the units that have not been
cancelled out.
78
1 ft
? ft  78 cm 1 in
ft
×
=
×
1
2.5 cm 12 in
30
Converting Between Units
1 ft = 12 in
1 in = 2.5 cm
Example #3: Convert 78 centimeters to feet.
Step 7) Divide the top by the bottom with a
calculator to get a decimal.
78
1 ft
? ft  78 cm 1 in
ft = 2.6 ft
×
=
×
1
2.5 cm 12 in
30